The leaders say FBI Director James Comey and the head of the National Security Agency will testify at a public hearing on March 20. He then went full-on Mellisa McCarthy, angrily countering that the media selectively chooses when to rely on statements from the intelligence committees. "I think you're going to find some very interesting items coming to the forefront over the next two weeks", Trump said.

Carlson challenged Trump, asking him why he wouldn't wait to tweet about a serious charge until he had evidence to support his statements.

The National Security Agency had partially met the committee's request with plans to fully comply by end of next week, Nunes said, but "the committee still has not received information requested from the CIA and Federal Bureau of Investigation... that is necessary to determine whether information collected on USA persons was mishandled and leaked".

But White House spokesman Sean Spicer said on Thursday the U.S. president maintained the allegation, adding: "He stands by it". The aide said Spicer is wrong.

Trump also refused to apologize for the White House's repetition of an unverified claim that Obama had employed a British spy agency to monitor him during the campaign.

It's not if they're treating us differently than another committee. They disagree on a variety of policies, including immigration, trade, defense spending and the role of the European Union, but on Friday the two were cordial.

Graham, of SC, is leading one of three congressional investigations into Russia's interference in the 2016 election.

"We're not here to listen to speeches", Nunes said.

Also Friday, the Senate intelligence committee announced a March 30 hearing in connection to its investigation into Russian activities during last year's presidential election.

Instead, Trump, standing alongside German Chancellor Angela Merkel, whose cellphone had been tapped by the Obama administration, said at a news conference: "As far as wiretapping, I guess, by this past administration, at least we have something in common, perhaps". "This is Nixon/Watergate. Bad (or sick) guy!", Trump wrote.

"Is it legal for a sitting President to be "wire tapping" a race for president prior to an election?"

In four separate statements on Twitter, Trump said he was the target of a wiretap.

"We've made clear to the administration that these claims are ridiculous and they should be ignored and we've received assurances that these allegations will not be repeated", May's spokesman told reporters.

The accusations - flatly denied by Obama - were at first seen as frivolous, spur-of-the-moment comments after a politically bruising week, which Trump and his team could later retreat from without much damage. He added that the president would ultimately be vindicated as investigations continue.

The president, who appears to have made his allegation in a burst of anger, has asked lawmakers to investigate the claim.

Donald Lambro is a syndicated columnist and contributor to The Washington Times.